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991.
992.
Osamu Kawase Yoshifumi Nishikawa Hiroshi Bannai Makoto Igarashi Tomohide Matsuo Xuenan Xuan 《Parasitology international》2010,59(2):211-216
Toxoplasma gondii is an obligate intracellular protozoan parasite that invades a wide range of host cells. The parasite releases a large variety of proteins from a secretory organelle, microneme, and the secretion is essential for the parasite invasion. We cloned a secreted protein with an altered thrombospondin repeat of Toxoplasma gondii (TgSPATR), which was the homologue of Plasmodium SPATRs. Immunofluorescence double staining experiment revealed that TgSPATR was co-localized with a microneme protein, MIC2, and immuno-electron microscopic (IEM) analysis detected TgSPATR in the microneme-like structure. TgSPATR secretion was induced by ethanol, while an intracellular Ca2+ chelator, 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid, tetraacetoxymethyl ester (BAPTA-AM), suppressed the ethanol-induced secretion, suggesting the secretion was Ca2+-dependent, similarly to known microneme proteins. Furthermore, TgSPATR, existed on outer surface of the parasites, was detected by incomplete membrane permeabilization by saponin and immunofluorescent antibody test (IFAT). Both TgSPATR and MIC2 were detected on outer surface of extracellular parasites, but not of intracellular single parasites, suggesting they were similarly secreted during early stages of parasite invasion. Therefore, TgSPATR is probably new member of microneme protein and maybe involved in parasite invasion. 相似文献
993.
The objective of this study is to describe the biogeochemical characteristics in the waters of Mongolian lakes, particularly
those related to parameters limiting phytoplankton growth and the trophic state. Investigations into the distribution of chemical
and biological parameters were carried out in the following 18 lakes: Har Us, Har, Hovsgol, Achit, Dalai, Bayan, Tolbo, Holboo,
Bust, Sangiyn Dalai, Tunamal, Dorgon, Uureg, Telmen, Hyargas, Uvs, Erkhel and Oygon, all of which showed a wide range of salinity
between 0.16 and 24.9 g l−1. Lake water was classified into four types: six fresh (less than 0.5 g l−1 salinity), three subsaline (0.5–3 g l−1), seven hyposaline (3–20 g l−1) and two mesosaline (20–50 g l−1) lakes. Predominant cations and anions in the order of dominance were Ca, Mg > Na > K and HCO3 > SO4, Cl in freshwater lakes, Na > Mg > Ca, K and HCO3, Cl > SO4 in subsaline lakes, and Na > Mg > K, Ca and Cl, SO4 > HCO3 in hyposaline and mesosaline lakes. Nitrogenous and phosphorus nutrients in the waters were low, seemingly caused by the
low loads from their watersheds, where the ground was free of vegetation with an extremely low level of human activity. The
present investigations revealed some 234 taxa of phytoplankton and 38 of zooplankton. The PC:PN:PP stoichiometric ratio by
weight was (22–202):(3–27):1. Phosphorus was assessed as the potential limiting parameter in eight lakes, nitrogen in six
and both nutrients in four others. Twelve lakes showed an oligotrophic character, while six were mesotrophic type. The six
oligotrophic lakes seemed to be subject to phosphorus limiting phytoplankton growth, four to nitrogen and two to both limitations.
In the mesotrophic lakes, on the other hand, phosphorus limitation was verified in two lakes, nitrogen in two others and both
in two lakes. 相似文献
994.
Ikeda O Sekine Y Mizushima A Nakasuji M Miyasaka Y Yamamoto C Muromoto R Nanbo A Oritani K Yoshimura A Matsuda T 《The Journal of biological chemistry》2010,285(49):38093-38103
STAP-2 (signal transducing adaptor protein-2) is a recently identified adaptor protein that contains pleckstrin homology (PH) and Src homology 2-like domains, as well as a STAT3-binding motif in its C-terminal region. STAP-2 is also a substrate of breast tumor kinase (Brk). In breast cancers, Brk expression is deregulated and promotes STAT3-dependent cell proliferation. In the present study, manipulated STAP-2 expression demonstrated essential roles of STAP-2 in Brk-mediated STAT3 activation. STAP-2 interacts with both Brk and STAT3. In addition, small interfering RNA-mediated reduction of endogenous STAP-2 expression strongly decreased Brk-mediated STAT3 activation in T47D breast cancer cells. The PH domain of STAP-2 is involved in multiple steps: the binding between Brk and STAP-2, the activation and tyrosine phosphorylation of STAT3, and the activation of Brk. Notably, a STAP-2 PH-Brk fusion protein exhibited robust kinase activity and increased activation and tyrosine phosphorylation of STAT3. Finally, STAP-2 knockdown in T47D cells induced a significant decrease of proliferation, as strong as that of Brk or STAT3 knockdown. Taken together, our findings are likely to inform the development of a novel therapeutic strategy, as well as the determination of novel prognostic values, in breast carcinomas. 相似文献
995.
Katsue Suzuki-Inoue Osamu Inoue Guo Ding Satoshi Nishimura Kazuya Hokamura Koji Eto Hirokazu Kashiwagi Yoshiaki Tomiyama Yutaka Yatomi Kazuo Umemura Yonchol Shin Masanori Hirashima Yukio Ozaki 《The Journal of biological chemistry》2010,285(32):24494-24507
CLEC-2 has been described recently as playing crucial roles in thrombosis/hemostasis, tumor metastasis, and lymphangiogenesis. The snake venom rhodocytin is known as a strong platelet activator, and we have shown that this effect is mediated by CLEC-2 (Suzuki-Inoue, K., Fuller, G. L., García, A., Eble, J. A., Pöhlmann, S., Inoue, O., Gartner, T. K., Hughan, S. C., Pearce, A. C., Laing, G. D., Theakston, R. D., Schweighoffer, E., Zitzmann, N., Morita, T., Tybulewicz, V. L., Ozaki, Y., and Watson, S. P. (2006) Blood 107, 542–549). Podoplanin, which is expressed on the surface of tumor cells, is an endogenous ligand for CLEC-2 and facilitates tumor metastasis by inducing platelet aggregation. Mice deficient in podoplanin, which is also expressed on the surface of lymphatic endothelial cells, show abnormal patterns of lymphatic vessel formation. In this study, we report on the generation and phenotype of CLEC-2-deficient mice. These mice are lethal at the embryonic/neonatal stages associated with disorganized and blood-filled lymphatic vessels and severe edema. Moreover, by transplantation of fetal liver cells from Clec-2−/− or Clec-2+/+ embryos, we were able to demonstrate that CLEC-2 is involved in thrombus stabilization in vitro and in vivo, possibly through homophilic interactions without apparent increase in bleeding tendency. We propose that CLEC-2 could be an ideal novel target protein for an anti-platelet drug, which inhibits pathological thrombus formation but not physiological hemostasis. 相似文献
996.
997.
998.
Kazuhiro Nakayama Takayoshi Shotake Osamu Takeneka Takafumi Ishida 《Journal of Mammalian Evolution》2010,17(3):211-214
Agouti is a common pigmentation phenotype in mammals including primates. Mutations in the agouti signaling protein gene (ASIP) are known to result in non-agouti black hairs in laboratory mice. It is still unclear whether sequence variation in ASIP is linked with the agouti/non-agouti phenotypes in macaques (Genus Macaca). To address this issue, we have determined and compared nucleotide sequences of protein coding region of ASIP in 18 macaque species and have identified 16 different sequences of the ASIP. Macaca nemestrina, which showed yellow agouti hairs, shared an identical amino acid sequence of ASIP with several non-agouti species. No sequence changes were found in functionally important sites of ASIP in the macaques showing non-agouti dark hair color. These results indicated that the variation in the protein coding region
of ASIP did not explain the non-agouti dark coat color in the macaques. Upstream regulatory regions of ASIP and other genes participating in pigmentation system remain to be investigated for the hair color variation in the macaques. 相似文献
999.
Sumiko Minobe Shingo Fukui Rumiko Saiki Tadashi Kajita Suchitra Changtragoon Nor Aini Ab Shukor A. Latiff B. R. Ramesh Osamu Koizumi Tsuneyuki Yamazaki 《Conservation Genetics》2010,11(1):301-310
To evaluate the genetic diversity of a mangrove species and clarify the genetic structure of its populations, we studied nucleotide
polymorphism in two DNA regions of Bruguiera gymnorhiza collected from the southern islands of Japan, Thailand, Malaysia, Indonesia, Micronesia, and India. The two DNA sequences
were the chloroplast (cp) intergenic spacer between trnL and trnF genes (ca. 300 bp), and a part (ca. 550 bp) of the nuclear gene coding for glyceraldehyde-3-phosphate dehydrogenase (GapCp). Little polymorphism was found within each of the three geographical regions, Pacific Ocean, Bay of Bengal and Arabian Sea.
Throughout the vast regions east of the Malay peninsula including Indonesia, Thailand, Micronesia and the southern islands
of Japan (Pacific Ocean), essentially only one haplotype (apart from variation in number of a T repeat) was present. A second
haplotype was present on the western coast of Malay Peninsula and the eastern coast of India (Bay of Bengal). On the southwest
of Malay Peninsula both of these haplotypes were present. Finally a third haplotype was found only on the western coast of
India (Arabian Sea). When taken over all geographic populations, total nucleotide variation within the species was large (μ = 0.006, average of the two genes). Our results are consistent with the hypothesis that this low genetic diversity within
any local population and differentiation between the different oceans or regions are caused by very low gene flow between
each of the different oceans coupled with frequent fluctuation of population sizes due to the change in sea level. The significance
of these results is discussed from evolutionary point of the mangrove forests. 相似文献
1000.
Kayoko Minakata Itaru Yamagishi Sanae Kanno Hideki Nozawa Masako Suzuki Osamu Suzuki 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(20):1683-1686
A rapid and sensitive electrospray ionization (ESI) tandem mass spectrometry (MS–MS) procedure was developed for the determination of iodide (I−). A gold (Au) and I− complex was formed immediately after the addition of the chelating agent NaAuCl4 to I− solution, and was extracted with methyl isobutyl ketone. One to five microliters of the extract were injected directly into an ESI–MS–MS instrument. I− quantification was performed by selecting reaction monitoring of the product ion I− at m/z 127 derived from the precursor ion 197AuI2− at m/z 451. I− concentration was measured in the quantification range from 10−7 to 10−5 M using 50 μL of solution within 10 min. Iodate was reduced to I− with ascorbic acid and determined. I− concentration in reference urine 2670a was measured after treatments. 相似文献